Method of closing collapsible tubes



March 16 1926.

N. M. HOPKINS METHOD oF'cL'osrNG coLLAPsIBLE TUBES all! Patented Ma'r.- 16, 1926.

UNITED STATES I 1,577,122 PATENT OFFICE.

.NEVIL MONROE HOPKINS, 0F NEW YORK, N. Y., .ASSIGNOR TO NEW-MIX PRODUC'I'S, 1 ING., OF NEW YORK, N. Y., A lCORPORATION OF DELAWARE.

METHOD OF CLOSING COLLRPSIBLE TUBES.

Application led October 1, 1923. Serial No. 666,000.

To all whom it may concern:

Be it known that I, NEVIL MONROE HOP- KINS, a citizen of the United States, residin at New York, in the county of New York and State of New York, 'have invented certain new and useful Improvements in Methods of Closing Collapsible Tubes; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable Others skilled in the art to which it appertains to makeh and use the same.-

This invention relates to collapsible tubes and methods of closing the same, and has for its Objects to improve the constructions and vprocedures heretofore known.

. With these and other:l objects in view, the invention consists in the novel article of manufacture comprising two collapsible tubes, one placed inside the other, and inv the novel steps and combinations of steps constituting the process, all as will be more fully hereinafter disclosed and particularly pointed out in the claims.

, Referring to the accompanying drawings forming a part of this specification in which like numerals designate like parts in all the views:

Figure 1 is a diagrammatic plan view of the open ended bottom lof a bi-compartment collapsible tube about to be compressed and sealed;

Fi re'2 is a view similar to Figure 1, showing the Open ends of the tubes partly compressed;

' Figure 3 is a plan view showing the parts represented in Figure 1 in a compressed relation;

Figure 4 is a partial sectional view taken on the line 4 4 of Figure 1, looking in the direction of the arrows;

Figure 5 is a partial sectional view taken on the line 5--5 of Figure 2, looking in the direction of the arrows;

Figure 6 is a partial sectional view taken on the line 6-6 of Figure 3, looking in the direction of the arrows;

Figure 7 is a much enlarged sectional view of the end of a tube sealed in accordance with this invention;

FigureS is a view Similar to Figure 7 of a tube as sealed prior to my invention; and

Figure 9 is an enlarged sectional view showing the relationship after compression of the inner and outer tubes illustrated in Figure 8.

In order that the precise invention may be the more clearly understood, it is said: I have invented what is known as bicompartment collapsible tu'bes for holding tooth pastes, face creams, shaving soaps, etc., which comprise inner and outer flexible containers concentrically disposed and adapted to extrude the two separated creams at their exit ends through contracted neck portions closed by the usual well known screw threaded caps. The other open bottom ends O-f these tubes, after illing, are compressed into a iattened portion by suitable dies and the attened ends of the tubes are then turned over in what i's known as a double turn, and over this double turn is placed and clamped tightly a metallic clip which seals effectively lthese bottom ends of the tubes. l

Heretofore, these bi-compartment tubes have been of such lengths that when the inner tube was placed within the outer tube before the closing operation the open bottom ended extremity of each tube was. A

in the same horizontal plane. After the cream materials were inserted in the respective tubes, the compression dies were then broughtv into action, pressing together or squeezing the open bottom ends of said tubes into a spread out flattened end portion. The flattened ends of the two tubes were then turned over together and a clip applied to seal the tubes.

However, it was found after the tubes had been made by machinery, filled with the cream materials, and their open ends compressed together, if the Open bottom edges 5 -and 6 occupied 4the same' plane before the compressing operation, that the edge 5 of the inner tube would extend beyond the edge 6 of the outer tube, after theA completion of said compressing Operation, as is diagrammatically illustrated in Figure 9. closed edges illustrated in Figure 9 were still further manipulated to form a complete seal by rolling up said edges 5 and 6, that the extended edge 5 in Figure 9 was It was also found that if the liable to become disposed in some such posifully explained hereinafter. By following the procedure new to be disclosed, however, these objections are obviated.

Referring to the drawings, 1 represents the open bottom end of an outer collapsible tube within which is placed the inner flexible tube 2, preferably having thinner walls than tube 1 and forming the bi-compartment tube 3 closed at its exit end as by the screw threaded cap 4. It will be observed from Figure 4 that the inner collapsible tube 2 1s so made that its bottom open end 5 does not reach the plane of the open bottom end 6 of tube 1. This is an important feature of the invention developed by experiment-ation and the purpose thereof will presently appear.

In closing the open bottom ends of these bi-eompartments collapsible tubes 3, the

tubes are brought between suitable compres-V sion dies 9 and 10 which are actuated by means not shown, so as to squeeze together the open ended portions of the said tubes 1 and 2, all as will be clear from Figures 1, 2 and 3. That is to say, Figure 1 shows a bicompartment tube upon which the closing compression dies 9 and 19 are about to act. In Figure 2, these dies 9 and 10 are shown as having advanced toward each other, thereby compressing or squeezing together for a certain distance the open ends of the tubes 1 and 2. Upon further movement of these compression dies, it will be seen from Figure 3 that ultimately the open bottom ends of said tubes will be compressed firmly together. The pressure is quite considerable in this operation, and inasmuch as the material of which the tubes are formed is of soft nature, there will be a distortation as well as a slight flow of metal when the open ends of the tubes 1 and 2 become pressed tightly together.

The respective tubes 1 and 2 being of different diameters as well as of diderent thicknesses, will cause different degrees of iow of the metal, and upon the application of pressure through the compressing dies 9 and 10 the outer tube 1 being of the larger dirneter will be first acted upon by the said les.

While the open end portions of a collapsible tube 1 are squeezed together as indicated in Figure 3, their outer edge will take on a more or less curved shape as diagrammatically indicated on an exaggerated scale by the line 6 in Figure 5. And if the open end portions of the inner tube 2 are also at the same time squeezed together, their outer edge will likewise take on a more or less curved shape as indicated on an exaggerated scale, by the line 5 in said Figure 5. But the tube 1 being of the larger di aineter its edge portion 6 will Hatten out to the points 26 and 27 which will be located much farther apart than will be the corresponding peints 29 and 30 on the flattened edge portions 5 of the tube 2. Since the lengths of the walls of the outer and inner tubes measured through said pairs of points 26 and 27, 29 and 30 must remain constant, and since the wall of the outer tube 1 is defieeted outwardly at said points 26 and 27 more than is the wall of the inner tube deflected outwardly at the points 29 and 30, it follows that the axial length of the outer tube will decrease more than will the axial length of the inner tube. i

It follows that if the inner and outer tubes are chosen initially of the lengths, as has been customary heretofore, or of such lengths as will cause their open uncompressed bottom edges to occupy the same plane, that the greater shortening of the outer tube under the closing operation described will cause the bottom edge portion 5 of the inner tube to project beyond the closed bottom edge portion 6 of the outer tube, as above stated, and as illustrated in Figure 9. Thus will an uneven pair of edges be presented for rolling over to form the final seal or closure as explained above. The satisfactory manipulation of this une-ven pair of edges is found in practice to be quite diiiicult, as will be clear from Figures 8 and 9. But this dilliculty has been overcome in this invention, as stated above by proceeding as follows.

Instead of providing an inner tube of such a length that its open bottom edge 5 will, before the closing operation, occupy the same plane as the open bottom edge 6, of the outer tube 1, l provide an inner tube 2 of such a. length that its edge 5 before filling and compressing, will occupy a plane below or inside the edge 6 as is illustrated in Figure 4. The distance the edge 5 should be located inside the edge 6 is readily determined by experiment or trial with a few tubes, but ordinarily a short distance of about one fourth of an inch or less will be found satisfactory, but in some cases a longer`- distance may be adopted.

With the lengths of the outer and inner tubes so determined that the open bottom edge 5 of the inner tube is located inside the outer open edge 6 of the outer tube and nearer to the exit end of the latter, the bottoms of the two tubes are subjected to the compression dies as above described. The compression in Fi re 5 has not been completed, so that the bottom edges 5 and 6 are still separated. But by referring to Figure 6, it will be seen that the distance between the said edges 5 and 6 has become still less, although the ed e 5 of the inner tube 2 has not yet reache the plane of the edge 6 of the outer tube 1, and although the dies 9 and 10, see Figure 3, have compressed the respective tubes to their closed positions.

After the bi-compartment tube 3 has been acted upon by the dies 9 and 10 as indicated in Figures 3 and 6, the dies recede from each other automatically by means not shown, thus releasing the said tube 3 whereupon it is advanced to the sealing mechanism also not shown. AThis mechanism takes the flattened portion 15 of the closed tube 8, and places a double turn therein, and then places over the double turn a clip 20, of a material much stronger and heavier than the tubes 1 and 2, see Figures 7 and 8. That is to say, a small portion of the attened end 15 of the tube 3 is turned over upon itself and then this double thickness of tube is turned over, thus forming three thicknesses of the tube 3 with the ends 5 and G of the respective inner andy outer tubes sealed within the turned over portion.

By'referring to Figure 7, it will be seen that the outer and inner walls 1 and 2 of the tube 3 are rst turned over to form the fold 21, which is then turned over to form the fold 22, around which is placed theclip 20, thus sealing the end of the tube 3. When an inner tube 2 shorter than the outer tube 1 has been used in accordance with this disclosure the ultimate seal will be as shown in Figure 7. That is to say, although the edge 5 of the inner tube 2 had not reached the edge 6 of the outer` tube 1, at the end of the this invention, it is necessary to have the" edge 5 of the inner tube located inside the edge 6 of the outer tube so that upon the completion of the several operations necessary to perform the closing and sealing of the open ends of these respective tubes, the end of the inner tube will not extend beyond the end of the outer tube.

It is obvious that those skilled in the art may vary the-details of the procedure as well as the arrangement of parts without departing from the spirit of the invention, and therefore I do not Wish to be limited to the above disclosure, except as may be required by the claims.

What l claim is:

1. The method of making al closure for the open bottom of a bicompartment collapsible tube consisting in dis-posing the openv bottom of the inner tube concentric with the open bottom of the outer tube and nearer to the exit end of the bicompartment tube than is the open bottom edge of the outer tube; and rolling up the bottom portions of both of said tubes.

l2. The method of making a closure for the open bottom of a bi-compartment tube, composed of an outer and an inner collapsible tube, which consists in disposing the bott-om edge of the inner tube nearer to the exit end of the first named tube than is the bottom edge of the outer tube; compressing said edges together; andprolling up the compressed edges. y

3. The method of making a closure for the open bottom of a bi-eompartment tube, composed of an outer and an inner collapsible tube, which consists in disposing the bottom edge of the inner tube nearer to the exit end of the irst named tube than is the bottom edge .of the outer tube; compressing said edges together; rolling up the compressed edges; and securing the rolled edges in place.

In testimony whereof I affix my signature.

NEVIL MONROE HOPKINS. 

